Request for advice, timing belt quandry

Cees Klumper · Post by **Cees Klumper** » 31 Aug 2025, 03:21

Because my issue is not restricted to this particular model Volvo, and because the sub-forum I have posted my question posting is rarely viewed, cross-posting here my question regarding a curious issue I, and others, have run into.

The issue is that after having replaced my timing belt, tensioner and idler pullies and water pump with quality parts, I now have a noise coming from the area and the belt slightly wanders back and forth across the pullies and camshaft 'gears'.
In an older thread on this subject, rspi said he sees the wandering a lot and not to worry about it, but the noise does worry me. The new pullies run absolutely smoothly and I did not have this noise before I replaced the belt etc.
A year ago I replaced the timing belt, water pump and pullies with quality parts from the same vendor, Skandix in Germany, on my other Volvo, a 2001 C70 T5, and that went flawlessly, no strange noises. I have replaced timing belts on other cars with no issues.

I have tensioned and re-tensioned the belt correctly for the current temperature; some say this kind of noise goes away if you under-tension the belt which seems wrong to me. The engine timing is spot on and the engine runs very smooth and strong. I have not over-tightened the tensioner pully, as some have suggested could cause the noise. There are no visible wear / chafing marks on the new belt (after having driven it maybe 250 miles since I did the job) and nothing is rubbing or touching anyplace. The sound must be either coming from one of the pullies (although they are brand new and run very smoothly when turning by hand on the bench) or is caused by the back-and-forth movement of the belt, is all I can figure.

I posted a short video here where you can hear the noise and see the timing belt 'wobble':

Grateful for any suggestions. I have to decide whether to get a complete new timing belt kit (probably I would order it straight from Volvo, just to rule out bad aftermarket parts risk) and do the job all over again, hoping it will remedy the noise, or just not worry about the noise and forget about it - as some have said they have done for 10K plus miles with no issues. I am not worried about the belt movement. Many suggest the belt movement is caused by the belt not being exactly straight/flat or some other quality issue. The belt is Hutchinson branded.

Post by **abscate** » 31 Aug 2025, 03:25

That’s a tough one. I’m still a bit jaundiced ftom my experience with a brand new iNA tensioner taking out a new cylinder head on my T5 in 3000 miles. Certainly worth watching

Hey, have you moved? Have you always been a west coast guy/gal?

Cees Klumper · Post by **Cees Klumper** » 31 Aug 2025, 04:02

Thanks Abscate! Just thought of something else to try which I will do next, I'm thinking maybe the noise is caused by the belt running up against the crankshaft pully, which is then pushing it back until it wanders back up against the pulley and so on, causing the noise. Should be fairly easy to test by holding something smooth against the side of the belt to prevent it from running up against the crankshaft pulley. If that is what causes the noise, I guess safe to drive until I can get a new timing belt kit. If that's not it, maybe I will re-install the old tensioner, it is still in great shape, until I can get a new one. The new one in there now may be an Ina (didn't save the box it came in).

We did move from France to Los Angeles back in 2018, but return to France every Summer, which is where I am now with the 2002 S80 and 2001 C70. We head back to Southern California next week, in 2023 we moved from living on a boat in Marina del Rey to a proper house in De Luz, near Temecula. We had a 2008 C70 in LA but sold it when we moved south. Before France we lived in Geneva Switzerland, where the S80 was originally sold, and before that in The Netherlands, where the C70 and my wife and I are originally from. I get all my Volvo parts from Skandix which is normally A-ok.

Cees Klumper · Post by **Cees Klumper** » 31 Aug 2025, 06:19

Update is I tried seeing if the noise would stop or at least change if I guided the belt with engine running (with a tire iron) so it would not keep running up against the crankshaft gear/pulley, but it made 0 diffrrence. I think I am going to play itsafe and order a new kit from Volvo. I could try replacing each part one by one, but it's a lot of work each time to just try.

Post by **scot850** » 31 Aug 2025, 08:27

Are you 100% sure the issue is the timing belt? Have you confirmed that by removing the serpentine belt and running the engine for a short time to see if the noise goes away? The reason I suggest this is I had an issue like this and it was the tensioner for the serpentine belt that failed after the timing belt swap.

Neil.

Cees Klumper · Post by **Cees Klumper** » 31 Aug 2025, 10:17

Thanks Neil - yes, unfortunately, I am positive. It was the first thing I checked - removed the serpentine belt, has 0 influence on the noise. The video I took without the serpentine belt on in fact. So it's definitely the timing belt / pulleys / water pump combo.

Vova585 · Post by **Vova585** » 31 Aug 2025, 11:25

I think we are not including vvt hub into the conversation. From video(at least to my eyes) it almost looks like belt movement starts somewhere between intake and exhaust side. I would obtain a dial(maybe cheaper clamping dial from HF for about $45) and check how much movement is in vvt hub. You can remove the belt and check with the dial movement in pulley, water pump..
P.s. after rewatching, tensioner would be my 1st suspect.

Cees Klumper · Post by **Cees Klumper** » 31 Aug 2025, 12:44

Thanks!
The reason I don't suspect the VVT hubs is I didn't touch them (other than making sure the timing marks lined up when I put the new belt on, so just a few degrees movement by hand) and the noise wasn't there before I changed the timing belt, pulleys and water pump. Also, the wobble seems most significant at the tensioner and idler pulleys, less so at the vvt hubs and water pump.

I think I've decided to re-install the old tensioner and idler pulleys tomorrow and will report back after. Much appreciate all the comments. I love this car and just want it to soldier on.

Cees Klumper · Post by **Cees Klumper** » 01 Sep 2025, 04:28

I re-installed the old tensioner pulley. Very little to no change, take a look and listen:

Bit at a loss. I am sure this noise wasn't there before I changed the belt, water pump and pullies (as I wrote before). The VVT hubs have no play and weren't touched. The belt wanders much less now, but the noise is still there. Nothing is touching, as far as I can tell, the back cover (the video is without serpentine belt and without top and front covers).
Only other thing I can think of is do it all over again with a new timing belt kit from Volvo. We're heading back to California this Saturday and the S80 will have to wait until next year. Disappointing! Others have reported just driving with the noise after their dealer told them "it's normal don't worry about it" without problems for 10K miles but it doesn't feel right to me at least, and a timing belt kit is not that expensive for peace of mind. I've gotten pretty good at it too, I've undone and re-installed the timing belt 3 times now ...

crasbe · Post by **crasbe** » 01 Sep 2025, 06:43

Just out of curiosity: what brand is the belt? Skandix is the vendor, but what is the belt manufacturer?